PRIOR CONCURRENT THERAPY: At least 1 week since treatment with any of the following: Diuretics Vidarabine Amphotericin B Aminoglycoside antibiotics Intravenous pentamidine Other known or potentially nephrotoxic agents Other investigational agents with anti-herpesvirus activity At least 4 weeks since systemic or local anti-herpesvirus therapy other than mucocutaneous acyclovir cream At least 4 weeks since systemic therapy for KS or other systemic or cutaneous malignancy At least 1 month since discontinuation of antiretroviral therapy Concurrent antiretroviral therapy allowed provided doses of the following, either alone or in combination, stable for at least 1 month prior to entry: AZT ddC 3TC ddI d4T protease inhibitor